<template>
  <div class="goods">
    <div class="menu-wrapper" ref="menuWrapper">
      <ul>
        <li v-for="(item,index) in goods" class="menu-item" @click="selectMenu(index,$event)" :class="{'current':currentIndex === index}">
          <span class="text border-1px">
            <span v-show="item.type>0" class="icon" :class="classMap[item.type]"></span>{{item.name}}
          </span>
        </li>
      </ul>
    </div>
    <div class="foods-wrapper" ref="foodsWrapper">
      <ul>
        <li v-for="item in goods" class="food-list food-list-hook">
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li v-for="food in item.foods" class="food-item border-1px">
              <div class="icon">
                <img width="57" heigh="57" :src="food.icon" />
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}份</span><span>好评率{{food.rating}}%</span>
                </div>
                <div class="price">
                  <span class="now">￥{{food.price}}</span>
                  <span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cartcontrol :food="food"></cartcontrol>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <shopcart ref="shopcart" :select-foods='selectFoods' :deliveryPrice="seller.deliveryPrice" :minPrice="seller.minPrice"></shopcart>
  </div>
</template>

<script type="text/ecmascript-6">

import BScroll from 'better-scroll';
import shopcart from '../shopcart/shopcart';
import cartcontrol from '../cartcontrol/cartcontrol'

const ERR_OK = 0;

export default {
  props:{
    seller:{
      type:Object
    }
  },
  data() {
    return {
      goods: [],
      listHeight:[],
      scrollY: 0
    };
  },
  computed: {
    currentIndex() {
      for(let i =0;i<this.listHeight.length;i++){
        let height1 = this.listHeight[i];
        let height2 = this.listHeight[i+1];
        if(!height2 || (this.scrollY >= height1 && this.scrollY < height2)){
          return i;
        }
      }
      return 0;
    },
    selectFoods() {
      let foods = [];
      this.goods.forEach((good)=>{
        good.foods.forEach((food)=>{
          if(food.count){
            foods.push(food);
          }
        });
      });
      return foods;
    }
  },
  created() {
    this.classMap = ['decrease','discount','special','invoice','guarantee'];
   
    this.$http.get('/api/goods').then((res)=>{
      res = res.body;
      if(res.errno === ERR_OK){
        this.goods = res.data;
        this.$nextTick(()=>{
          this._initScroll();
          this._calulateHeight();
        })
      }
    })
  },
  methods: {
    _initScroll() {
      this.menuScroll = new BScroll(this.$refs.menuWrapper, {
        click: true
      });
      this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
        click:true,
        probeType: 3
      });
      this.foodsScroll.on('scroll',(pos)=>{
        this.scrollY = Math.abs(Math.round(pos.y));
      })
    },
    _calulateHeight() {
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let height = 0;
      this.listHeight.push(height);
      for(let i =0;i<foodList.length;i++){
        let item = foodList[i];
        height += item.clientHeight;
        this.listHeight.push(height);
      }
    },
    selectMenu(index,event) {
      if(!event._constructed){
        return;
      }
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let el = foodList[index];
      this.foodsScroll.scrollToElement(el,300);
    },
    addFood(target){
      this._drop(target);
    },
    _drop(target){
      // 体验优化，异步执行下落动画
      this.$nextTick(()=>{
        this.$refs.shopcart.drop(target);
      });
    },
    _followScroll(index) {
      let menuList = this.$refs.menuList;
      let el = menuList[index];
      this.meunScroll.scrollToElement(el, 300, 0, -100);
    }
  },
  components:{
    shopcart,
    cartcontrol
  }
}
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../common/stylus/mixin.styl";

  .goods
    display flex
    position absolute
    top 174px
    bottom 46px
    width 100%
    overflow hidden
    .menu-wrapper
      flex 0 0 80px
      width 80px
      background #f3f5f7
      .menu-item
        display table
        height 54px
        width 56px
        padding 0 12px
        line-height 14px
        &.current
          position relative
          margin-top -1px
          z-index 10
          background #ffffff
          font-weight 700
          .text
            border-none()
        .icon
          display inline-block
          vertical-align middle
          width  12px
          height 12px
          margin-right 2px
          background-size 12px 12px
          background-repeat no-repeat
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')  
          &.guarantee
            bg-image('guarantee_3')
          &.invoice
            bg-image('invoice_3')
          &.special
            bg-image('special_3')
        .text
          display table-cell
          width 56px
          vertical-align middle
          border-1px(rgba(7,17,27,0.1))
          font-size 12px
    .foods-wrapper
      flex 1
      .title
        padding-left 14px
        height 26px
        line-height 26px
        border-left 2px solid #d9dde1
        font-size 12px
        color rgb(147,153,159)
        background #f3f5f7
      .food-item
        display flex
        margin 18px
        padding-bottom 18px
        border-1px(rgba(7,17,27,0.1))
        &:last-child
          border-none()
          margin-bottom 0
        .icon
          flex 0 0 57px
          margin-right 10px
        .content
          flex 1
          .name
            margin 2px 0 8px 0px
            height 14px
            line-height 14px
            font-size 14px
            color rgb(7,17,27)
          .desc, .extra
            line-height 10px
            font-size 10px
            color rgb(147,153,159)
          .desc
            margin-bottom 8px
            line-height 12px
          .extra
            .count
              margin-right 12px
          .price
            font-weight 700
            line-height 24px
            .now
              margin-right 8px
              font-size 14px
              color rgb(240,20,20)
            .old
              text-decoration line-through
              font-size 10px
              color rgb(147,153,159)
          .cartcontrol-wrapper
            position absolute
            right 0
            bottom 12px
</style>
